Pyrocat PMK question

[Oldtimer Jay]

Hi All,

I like both Pyrocat and PMK a lot and am trying to ruduce the number of bottles of stock solutions on my shelf. What I am wondering is if I can use the Pyrocat solution B which is 100 G. potasium carbonate in 100 Ml. water in place of the PMK solution B which is 30 G. of sodium metaborate in 100 Ml. of water?
If so, at what ratio should I use the PMK A to B solutions? The ratio is 1 part A to 2 Parts B diluted with 100 parts water for the sodium metaborate solution, but the Pyrocat Part B seems more concentrated.
Yes, I could mix up the Sodium metaborate solution more quickly than ask this question, but I truly am trying to reduce chemical bottle clutter as much as possible and thought that if the Pyrocat Part B could be used for PMK that would be a small step in the right direction.

Thanks in Advance,

Jay L.

 

[noseoil]

Jay, great question. To answer truthfully, I have no idea. That having been said, I would just try a reduction of the pyrocat B as 1/3 of the normal amount for the PMK with a film test. A snip test with 35mm should tell you what happens. I'm sure one of our resident chemists can enlighten us as to reactivity, combined working solution life, etc. If you do the test, please let us know what you find. I use both developers and would be curious. My problem would be getting the wrong ratio, so I'll keep mine as the only two developers that I use. Still the best of both worlds, IMO. tim

 

[gainer]

Hutchings in his Book of Pyro has comments about his trials of various alkalis. You may find more fog using the carbonate with PMK. TEA can work pretty well with PMK, so if you have TEA on hand for mixing Pyrocat MC, you can still have the same number of bottles.

 

[vet173]

I fixed that problem by cutting it down to just pyrocat.

 

[gainer]

Hutchings in his Book of Pyro has comments about his trials of various alkalis. You may find more fog using the carbonate with PMK. TEA can work pretty well with PMK, so if you have TEA on hand for mixing Pyrocat MC, you can still have the same number of bottles.

I just tested the PMK-TEA combo. I does work well. As to whether you switch permanently, it's a matter of -- I was about to say taste, but I mean color. I even mixed up some Pyrogal MC, just to see what happened, subbing pyrogallol for catechol. I think it was a little too foggy, and I know it's a different color, but I had to try.

 

[sanking]

Hi All,

I like both Pyrocat and PMK a lot and am trying to ruduce the number of bottles of stock solutions on my shelf. What I am wondering is if I can use the Pyrocat solution B which is 100 G. potasium carbonate in 100 Ml. water in place of the PMK solution B which is 30 G. of sodium metaborate in 100 Ml. of water?
If so, at what ratio should I use the PMK A to B solutions? The ratio is 1 part A to 2 Parts B diluted with 100 parts water for the sodium metaborate solution, but the Pyrocat Part B seems more concentrated.
Yes, I could mix up the Sodium metaborate solution more quickly than ask this question, but I truly am trying to reduce chemical bottle clutter as much as possible and thought that if the Pyrocat Part B could be used for PMK that would be a small step in the right direction.

Thanks in Advance,

Jay L.

Using the Pyrocat B solution with PMK A would give a working solution with a pH much higher than necessary for pyrogallol + metol. It would work, but you would need a lot of restrainer to cut back on fog, which would be quite high as Pat mentioned.

Using the PMK B solution with Pyrocat Stock A won't work at all, as the pH is much too low for pyrocatechin + phenidone.

Sandy King

 

[fhovie]

Chemical bottle clutter is an important ingredient to the chaos of the creative process. That is why so many artists mix their own.

.... hummm

 

[sanking]

I just tested the PMK-TEA combo. I does work well. As to whether you switch permanently, it's a matter of -- I was about to say taste, but I mean color. I even mixed up some Pyrogal MC, just to see what happened, subbing pyrogallol for catechol. I think it was a little too foggy, and I know it's a different color, but I had to try.

I assume it is slightly less active than with the regular 30% metaborate Stock B?

I found this true with the PC-Glycol versus PC-TEA solution. Using the metaborate B solution increased activity (and decreased time of develpment) by about 15-20%. PC-Glycol with the 30% metaborate is Tmy developer of choice for all sheet film I don't develop in Pyrocat-HD or -MC. Very simple to mix and very economical.

Sandy

 

[gainer]

Maybe so. I wasn't that critical. I used a film I had not previously used with PMK and lucked out with 10 min at 70 F, agitated 5 sec per minute. The film was a 100 ISO from Freestyle under the Arista II label, which I'm not sure is available now, but FP4+ ought to behave about the same. The negative printed well without filtering and had all the gradations I wanted.

That PMK was several years old in a half-full pint bottle. I do like Pyrocat MC better. I don't have much to do with blue or UV printing, but I do think the tanning and stain help with VC printing as well.